Key-hole guard



(No Model.)

W. W. BROGA.

KEY HOLE GUARD.

No. 336,789. Patented Feb. 23, 1886.

WITNESSES WzZZz'am B2090,

l .dttorneys.

N. PETERS. fina -M mma. Wnhinglon. In.

2 Sheets-Sheet 1.

2 SheetsSheet 2.

(No Model.)

W. 'W. BROGA.

KEY HOLE GUARD.

Patented Peb. 23, '1886.

in 7////////A 2 El JWVL TOR y QM Z119 flttorneys. Y

WITNESSES N. PETERS, Pholn-lilhogfipher. Wflhingtom D. C.

UNITED STATES PATENT OFFICE.

XVILLIAM \VALLAGE BROGA, OF OTIS, MASSACHUSETTS.

KEY-HOLE GUARD.

SPECIFICATION forming part of Letters Patent No. 336,789, d ted February23, 1886.

Application filed July 22, 1885.

To rrZZ whom it may concern.-

Be it known that I, WILLIAM W. BROGA. a citizen of the United States,residing at Otis, in the county of Berkshire and State of Massachusetts,have invented a new and useful Improvement in Key-Hole Guards, of whichthe following is a specification, reference being had to theaccompanying drawings.

This invention relates to an improvement in key-hole guards; and itconsists in the peculiar construction and combination of parts that willbe hereinafter set forth, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a side elevation of a lockembodying my invention, with the inner face removed and the boltwithdrawn. Fig. 2isasimilar view showing the bolt extended when locked.Fig. 3 is a side elevation of the lock with the outer face removed. Fig.4is averti cal longitudinal central sectional view. Fig. 5 is averticalcrosssect-ional view taken on the line at m of Fig. 1. Figs. 6, 7, and 8are detail views.

A represents the lock-case, which is preferably rectangular in shape,andis provided with the inner face, B, and the outer face, 0. The innerface, B, has the key-hole D, and the outer face, 0, has a similarkey-hole, E, which is in line with the key-hole D.

F represents a circular plate, which is countersunk in the inner side ofthe outer face, O, and is pivoted centrally on a stud, O, the inner endof which is formed into aheaded plate, P, which is provided with anopening, R, that registers with the key-hole. An opening, H, is made inone side of the circular plate F, which corresponds to the key-hole, andon one side of said plate F is a cutaway portion or slot, I, in whichworksa. stud, K, that projects inwardly from the outer face of thelock-case. On the opposite side of the plate F from the opening H is alongitudinal slot, L, which has at one end a communicating angular arm,M, and at the opposite end a communicating arm, N, which is at rightangles to said slot.

S represents a sliding bolt, which is secured in lock-case between thestuds a. The inner end of this bolt is provided with a notch, T, whichis rounded on its sides, at the outer end thereof, as shown. Apivotalstud, U, projects from one side of. this bolt toward the outer face ofthe lock cas'e, and on this pivotal stud is Serial No. 172,315. (Nomodel.)

fulcrumed an arm, V, which is provided at its rear extremity with stud\V, which engages normally with the slot L of the plate F. On a stud, b,is pivoted a tumbler, A, against the outer end of which, on the upperside thereof, bears a spring, B. A stud, Z, projects from the face ofthe bolt S, opposite the arm V, and this stud enters an open slot. 0, inthe outer end' of the tumbler. Notches D are made at the inner end ofthis open slot, and similar notches, E, are made at the outer endthereof.

The operation of my lock is as follows: In order to open or close thelock, I use a key, F, the web of which is provided on its outer side, atits outer end, with a notch, f, which corresponds in width with thethickness of the inner end of the arm V. Theiuner side of said web isprovided at its outer end with a projection, f, which is only aboutonehalf as deep as the notch f. Vhen the key isinserted into thekey-hole from the inner side of the lock-case and turned, the notchfpasses over the inner end of the arm V without moving said arm, and theweb of the key enters the notch T of the bolt S. Just before actuatingthe bolt the key bears against the under side of the tumbler A, and, assaid key is turned, raises the tumbler against the pressure of thespring B and releases the stud Z from the upper inner notch, D, the boltto be moved into the position shown in Fig. 2, when the tumbler ispressed downwardly by the spring B, and causes the outer upper notch, E,to engage the stud Z, and thereby secure the bolt against inward movement until the tumbler has been raised. A spring, G, bears against thearm V, which spring, when the bolt is in its initial position, causesthe stud W to bear in the angular arm M of the slot L in plate F. As thebolt is moved forward, as hereinbefore described, the stud W partlyrotates the plate F, and causes said plate to close the key-hole on theouter side of the lock, and thereby effectually prevents the lock frombeing picked by any person on the outside. When the key is inserted inthe outer side of the lock, the projection f moves the free end of thearm V upwardly, so

into the slot L. .As the key continues to turn, the tumbler is raised torelease the bolt S, as hereinbefore set forth, and as the bolt moves asto move the stud W out of the bent arm M and so as to free it and allowmy invention, I

a the inner and the outer face, 'of thesIiding bolt,

the plate F, pivoted to the case and having the opening H, and the slotL, having the angular arm M, and the arm V, pivoted to the bolt S, andhaving a stud, WV, engaging in the slot of the plate F, whereby saidplate is retated to close the key-hole when the bolt is moved by a keyinserted in the inner side of 20 the look, substantially as described.

2. The combination, with the case, the sliding bolt, the plate F,pivoted to the case and having the opening H, that registers with thekey-hole when the bolt is withdrawn, and the slot L, of the arm V,having a stud entering the said slot, substantially as described.

3. The combination, with the look-case, the bolt having the stud Z, andthe tumbler engaging said stud, of arm V, pivoted to the bolt, and theplate F, pivoted to the look-case and connected to arm V, to close thekey-hole when the bolt is moved, substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixedmy signature in presence of two witnesses.

\VILLIAM WALLACE BR-OGA.

\Vi tnesses:

HENRY W. TAFT, CHAS. W. STRONG.

